weird problem : pete 388 has a plastic (i guess ) top tank/expansion tank -- when coolant gets hot, it will push out the fill cap,which is a plastic non vent cap (plastic cap with a rubber gasket). The overflow/expansion side, which has a pressure cap, (15 lbs.) has no coolant in it. the system seems to hold pressure -- open either cap a day or two after shut down and get an audible "hiss" . I can't figure this out. makes a mess when it drips down tank and shroud etc. 525
How full are You filling the tank. Where is the line on the tank and what does it say above the line.
approx. a 1/4 inch BELOW the Min. fill line. any lower and the low coolant warning comes on,at cold start
ck for head problem or compressor